Kevin 11

Kevin 11 was originally a human with the ability to absorb energy to use it for himself. But after a fight with Ben, he accidentally absorbed the Omnitrix's power allowing him to shape shift into the 10 aliens of the Omnitrix. But, he used his powers for too long and all the 10 aliens' DNA got mixed into his own DNA, turning him into a freak, permanently. But he has all the 10 aliens' DNA:
Fourarms's body structure and his left eyes
Diamond head's right arm
Heatblast's left arm
Wildmutt's lower arms
Upgrade's back
Stinkfly's wings
Ripjaw's antennae
Grey matter's right eye
Ghostfreak's eye tracks
XLR8's tail
But, his powers have a downfall. Because he has 10 aliens' DNA, he only has 1 tenth of every aliens' powers. But, by combining his powers together, it makes up for his loss of power. For example: He can combine Stinkfly's goo+Heatblast's fire to create an explosive.